Variable profile air bag restraint

ABSTRACT

An air bag assembly for cushioning restraint of an occupant in a vehicle during an impact event. The air bag assembly includes an inflator activatable to discharge inflation gas upon the occurrence of predetermined vehicle conditions and an air bag cushion including an interior surface in fluid communication with the inflator such that upon discharge of inflation gas from the inflator the air bag cushion is inflated to a deployed state. At least one profile restraining tether element is operatively connected to the air bag cushion such that the profile restraining tether element restrains the expansion of the air bag cushion upon introduction of the inflation gas to the air bag cushion. The profile restraining tether element is also releasably anchored to a substantially stationary retaining member so as to shorten the operative length of the profile restraining tether element such that the air bag cushion is inflatable to a first restrained depth when the profile restraining tether element is anchored to the retaining member. The profile restraining tether element is releasable from the retaining member upon the occurrence of predetermined occupant conditions at the time the air bag cushion is deployed such that the air bag cushion is inflatable to a second depth which is greater than the first restrained depth.

TECHNICAL FIELD

[0001] This invention relates to an air bag restraint system, and moreparticularly to an air bag restraint system which controls the expansioncharacteristics of an inflatable air bag cushion discharged therefromsuch that the inflated profile of the discharged air bag may be variedbased upon the size and/or position of the vehicle occupant to beprotected.

BACKGROUND OF THE INVENTION

[0002] It is well known in the prior art to provide an air bag assemblyincluding an inflatable air bag for protecting the occupants of atransportation vehicle. In an automotive vehicle such air bag assembliesare typically located within the hub of the steering wheel and in arecess in the vehicle instrument panel for protection of the vehicleoccupants seated in opposing relation to such assemblies. Additional airbag assemblies may be located within the seats and/or door panels forprotection of the occupants during a side-impact event. It is also knownto utilize inflatable curtain-like structures for deployment from thestructural pillars or roof line of the motor vehicle so as to promoterestraint and protection of the vehicle occupant during a roll-overevent.

[0003] Air bag assemblies typically include an inflatable cushion influid communication with a gas emitting inflator. Upon sensing certainpredetermined vehicle conditions, such as a certain amount of vehicledeceleration, the inflator discharges a fixed amount of inflator gasthereby forcing the air bag into a deployed position. The inflator gasoccupies the available volume within the air bag cushion thereby forcingthe air bag cushion to expand outwardly to the extent permitted by itsconstruction. The pressure within the air bag cushion upon deployment isproportional to the quantity of inflator gas expelled into the air bagand inversely proportional to the volume occupied by the inflator gaswithin the air bag. As the occupant comes into contact with the expandedair bag, the inflator gas is forced out of the air bag therebydissipating the kinetic energy of the occupant.

[0004] In some cases, it may be desirable to provide an inflator thathas varied levels or stages of inflator gas output in response to thesensing of different vehicle or occupant conditions. Thus, it isgenerally known in the prior art to provide multi-stage inflators thatdischarge inflation gas at variable levels depending upon the conditionspresent during deployment. However, these multi-stage inflators are morecomplex than typical inflators. Moreover, the use of such multi-stageinflators provides control over only the amount of inflator gas which isdischarged and does not provide control over the expanded geometry ofthe inflated air bag cushion. That is, so long as the air bag has afixed expanded geometry, the inflator gas will tend to fill theavailable capacity and the expanded configuration of the air bag will begenerally the same even if the quantity of inflator gas is variedalthough the pressure within the air bag will tend to differappreciably.

[0005] In order to provide an additional degree of freedom in thecontrol of air bag performance, it has been suggested to utilize air bagcushions which incorporate seams within the air bag to control theexpanded geometry of the inflated air bag wherein the seams separateupon the introduction of sufficient force across the seams therebyfreeing the air bag cushion from the restraint imposed by the seams atlower pressures. In order for such break-away seams to providecontrolled expansion, the application of such seams must be performedwith substantial precision such that seam separation will occur in ahighly reproducible and predictable manner. As will be appreciated, dueto the large number of variables involved in the introduction andseparation of such break-away seams, such requisite precision andreproducibility may be difficult to achieve.

SUMMARY OF THE INVENTION

[0006] The present invention provides advantages and alternatives overthe prior art by providing an assembly to vary the deployed profile ofan air bag cushion which may be inflated to a controlled variable levelusing either a single stage or multi-stage inflator and which may beexpanded preferentially in the depth direction towards the occupant tobe protected without the need to rely exclusively on break-away seams.The present invention thereby provides an air bag cushion which may bedeployed to a relatively shallow profile for protection of a smallstature occupant or an occupant seated in close proximity to the air bagand which may also be deployed to a relatively increased depth forprotection of a larger occupant or an occupant seated further away fromthe location of air bag deployment. According to a potentially preferredfeature, the present invention further provides a mechanism for simplyand effectively controlling both the profile of the deployed air bagcushion and the quantity of inflation gas released into the air bagcushion.

[0007] According to one potentially preferred feature, this inventionprovides an assembly to deploy an air bag cushion to a controlledgeometry of a depth which is desired in view of the position and/or sizeof the occupant to be protected such that an air bag of substantialdepth is available to protect occupants such as larger stature personswho may be seated further away from the location of cushion deployment,while a smaller air bag volume of diminished depth is available toprotect occupants such as smaller stature persons who may be seatedcloser to the location of cushion deployment.

[0008] According to a further potentially preferred feature, the presentinvention may provide an effective mechanical actuation mechanism toadjust the deployment characteristics of the air bag cushion whichactuation mechanism is not dependent upon a particular cushionconstruction technique and which may be activated based upon measuredparameters of the occupants to be protected and/or upon the severity ofthe collision event taking place.

[0009] According to yet a further potentially preferred feature of thepresent invention, the actuation mechanism to control the deployedprofile of the air bag cushion may be operated either independently orin conjunction with a device to adjust the level of inflator gas whichenters the air bag cushion thereby providing additional versatility ofoperation. Conjunctive operation may be carried out utilizing a singlecommon initiator such as a pyrotechnic squib. Thus, it is a feature ofthe present invention that the air bag assembly may incorporate as fewas two initiators. That is, one initiator is used to activate theinflator and one initiator is used to initiate the actuation mechanismto control the deployment profile of the air bag and the level ofinflation gas which enters the air bag.

[0010] According to a further potentially preferred feature of thepresent invention, the actuation mechanism to control the deployedprofile and level of inflation gas may be mounted externally on theinflator or the supporting housing thereby avoiding any need tosubstantially modify the shape or construction of the inflator housing.In addition, the actuation mechanism and variable profile air bag of thepresent invention may be used in conjunction with traditional singlestage inflators without requiring internal modifications to suchinflators.

[0011] According to one aspect of the present invention, theseadvantages and features are accomplished in a potentially preferred formof the present invention by providing an inflatable air bag expandableto a first volume and depth which first volume and depth may berestrained to a second diminished volume and depth by tethers which areattached at locations across the surface of the air bag cushion andwhich are releasably attached to a releasable anchor assemblyindependent from the air bag cushion. Based upon appropriate measuredparameters such as the size and/or position of the occupant to beprotected, the severity of the collision event and/or the use or nonuseof recommended seat belts, an actuation mechanism which releases thetethers from the anchor assembly may be either activated or may remaindeactivated to yield a deployed air bag cushion of desired volume andgeometric configuration. The volume of inflation gas entering the airbag cushion may be adjusted simultaneously with the profile of the airbag cushion.

[0012] According to the potentially preferred form of the invention, theactuation mechanism will remain deactivated and thereby result in aconstrained final expanded geometry in the event that the occupant to beprotected is either of small stature and/or is seated in a positionclose to the location of air bag deployment or has traveled into such aclose position as a result of nonuse of a safety harness. In the eventthat the occupant to be protected is of larger stature and/or is seatedfurther away from the location of air bag deployment, the actuationmechanism may be activated to at least partially eliminate volumetricrestraint thereby permitting the air bag to expand to a greater volumeand depth so as to provide additional cushioning for such an occupant.

[0013] Thus, it will be appreciated that variable expanded geometriesmay be achieved in the inflated air bag with such geometries beingcontrollable and adjustable based upon the parameters of the occupant tobe protected and the collision event taking place. Such control ispreferably achieved through use of one or more mechanical actuationmechanisms which are either activated or deactivated to effect controlof the inflatable air bags by either holding or releasing tetheringrestraint elements from an anchoring location remote from the air bagcushion.

[0014] Since the activation or deactivation of the actuation mechanismis carried out in conjunction with deployment of the air bag cushion,the necessary geometric character may be achieved for a given occupantas may be present within the vehicle at the time of deployment. Thus,the variable air bag and actuation mechanism according to the presentinvention offers substantial versatility in the protection of largenumbers of diverse occupants including very small and very largeoccupants. It will also be appreciated that this system provides asimple, cost effective and highly reproducible system for controllingthe volume of deployed air bag cushions even when using a traditionalsingle stage inflator.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will now be described by way of exampleonly, with reference to the accompanying drawings which constitute apart of the specification herein and in which:

[0016]FIG. 1 is a cut-away view of a vehicle interior showing an air bagcushion in a stored undeployed state in opposing relation to a vehicleoccupant;

[0017]FIG. 2 is a cut-away view of an air bag module including aninflator and an actuation mechanism for controlling the expansion of avariable profile air bag as well as controlling the quantity of inflatorgas which enters the variable profile air bag;

[0018]FIG. 3A illustrates an arrangement of profile restricting tethersas may be utilized in a variable profile air bag wherein the air bag isrestrained to a diminished profile;

[0019]FIG. 3B is a view similar to FIG. 3A, wherein the air bag is in anexpanded profile configuration;

[0020]FIG. 4A illustrates an arrangement of profile restricting tethersas may be utilized in a variable profile air bag, wherein the air bag isrestrained to a diminished profile; and

[0021]FIG. 4B is a view similar to FIG. 4A, wherein the air bag is in anexpanded profile configuration.

[0022] While the invention has been illustrated and generally describedabove and will hereinafter be described in connection with certainpotentially preferred embodiments, it is to be understood that in noevent is the invention to be limited to such illustrated and describedembodiments. On the contrary, it is intended that the present inventionshall extend to all alternatives and modifications as may embrace theprinciples of this invention within the true spirit and scope thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Turning now to the drawings, wherein to the extent possible likereference numerals are utilized to designate like components throughoutthe various views, in FIG. 1 it is seen that a vehicle 110 may include aseating structure 112 which supports an occupant 114 in generallyopposing relation to an instrument panel 116. An inflatable air bag 120may be housed within the instrument panel 116 for outward deploymenttowards the occupant 114 in the event of a collision.

[0024] While the air bag 120 is illustrated for descriptive purposes inrelation to a vehicle passenger, it is to be understood that the presentinvention is in no way intended to be limited to a passenger sideconfiguration. On the contrary, it is contemplated that the presentinvention may have equal applicability to air bag deployment in opposingrelation to the operator (not shown) of the vehicle from the steeringcolumn (not shown) as well as in relation to air bags deployed fromother regions within the vehicle interior including, by way of exampleonly, side-impact air bags and inflatable curtain structures.

[0025] It is contemplated that the vehicle interior will preferablyinclude a seat position sensor 122 as the primary means of detecting theposition of the occupant 114 relative to the instrument panel 116. It isfurther contemplated that the vehicle 110 may include additionalposition sensors such as an optical scanner 124 or the like to measureboth the volume and position of the occupant to be protected. It iscontemplated that the interior of the vehicle 110 may also be providedwith a scale 126 disposed within the seating structure 112 so as toprovide additional data regarding the load to which the inflatable airbag 120 may be subjected. The seating structure 112 may also be providedwith sensing elements to measure the degree to which the seatingstructure 112 is reclined. A deceleration meter 127 as will be wellknown to those of skill in the art may be utilized to measure therelative severity of the collision event which may give rise to thedeployment of the inflatable air bag 120. The vehicle 110 may also beprovided with sensors to determine and communicate whether or not theoccupant is utilizing the recommended seat belt structures 128. The dataso collected may be utilized to determine desirable expanded profilecharacteristics for the air bag 120 according to the present invention.

[0026] In general, it is believed that in some instances persons ofsmall stature may benefit if the air bag 120 according to the presentinvention is of a reduced profile upon deployment due to the fact thatsuch occupants have a lower body mass and are generally seated in closerproximity to the instrument panel 116. Conversely, it is believed thatin some instances, occupants of larger stature may benefit from a deeperprofile air bag 120 due to their enhanced mass and propensity to bepositioned further from the location of air bag deployment. However, inthe event that a person of smaller stature is seated at a remotedistance from the location of air bag discharge, the air bag 120 willpreferably assume an extended profile so as to span the distance betweenthe occupant and the location of discharge. Likewise, a person of largerstature who is seated in unusually close proximity to the location ofair bag discharge may benefit from a shallow inflated profile.

[0027] The determination of the potentially desirable profile characterof the air bag 120 for various occupants seated in various positions maybe determined based upon event simulations utilizing so-called “crashdummies” of various sizes in various positions within the vehicle 110.Such size and position parameters may be stored along with correspondingdesired gas emission characteristics within an electronically accessiblestorage registry for access by a processing unit such as an on-boardcomputer during a collision event. During such an event, the position ofthe occupant 114 as measured by the seat position sensor 122 as well asany other sensors as may be utilized will be correlated to correspondingvalues as archived within the storage registry thereby providing data onthe desired profile characteristics of the air bag 120 for the occupant114 based on the conditions of the occupant 114 including the severityof the collision event to which the occupant 114 is being subjected andhis or her relative orientation within the interior of the vehicle 110at the time the event takes place.

[0028] According to a potentially preferred form of the invention, theair bag 120 will have a first expanded profile which is restrained tosome degree by tethered restraints 130 (FIGS. 3B, 4B) and at least asecond expanded profile which is characterized by less depth and lowervolume than the first expanded profile (FIGS. 3A, 4A). Such diminishedprofile and volumetric capacity is preferably achieved by anchoring thetethered restraints to some releasable anchoring point remote from theair bag thereby shortening the operative length of tethered therestraints 130 which control the expanded profile of the air bag 120.The operative length of the restraints 130 is lengthened when suchtethered restraints 130 are released from the anchoring point in themanner to be described further hereinafter. However, such tetheredrestraints preferably continue to provide some degree of restraint overthe profile of the air bag 120 subsequent to release from the anchoringpoint.

[0029] For a given collision event, the release or retention of thetethered restraints 130 is preferably carried out during inflation ofthe air bag 120 based upon the preferred profile character of the airbag 120 in view of the measured physical character and position of theoccupant 114. That is, if the physical character and orientation of theoccupant 114 are such that previously collected data indicates that adeep profile and corresponding larger volume are desired for theinflatable air bag 120, then the tethered restraints 130 are releasedfrom their anchored position during inflation thereby permitting theinflatable air bag 120 to assume an expanded enhanced profile.Conversely, in the event that the physical character and orientation ofthe occupant 114 is such that the inflatable air bag 20 is preferably ofa more shallow profile and lower volume, then the tethered restraints130 will remain anchored during deployment of the inflatable air bag 120so as to restrain the final profile thereof.

[0030] Looking to FIGS. 2, 3A, and 3B, the tethered restraints 130 maybe attached to an anchor strap 131 as shown. The anchor strap 131preferably formed into a loop 133 which is optionally held within a ringelement 132. As shown, in the event that a ring element is utilized, theattachment between the ring element 132 and the anchor strap 131 may beattained by passing the anchor strap through the opening at the interiorof the ring element 132 so as to form the loop 133 which can slide alongthe length of the ring element 132. The configuration of the loop 133 isthereafter maintained by attaching the overlapping portions of anchorstrap 131 to one another along a length remote from the loop 133. Thejoiner between portions of the anchor strap 131 to maintain the loopedconfiguration may be by any suitable joining technique as may be knownto those of skill in the art including, by way of example only, theapplication of a sewn seam 134 as may be applied using industrial sewingequipment. Other modes of attachment may include adhesive bonding,ultrasonic welding, RF welding, and combinations thereof. As will beappreciated, while the use of an anchoring strap 131 may be desirable insome instances to connect the tethered restraints 130 to a releasableanchor point, it is likewise contemplated that such an anchor strap maybe eliminated if desired in which instance the tethered restraints maybe attached directly to the releasable anchor.

[0031] The material forming the tethered restraints 130 and the anchorstrap 131 is preferably of pliable nature such as a woven or knittedtextile of construction resistant to substantial elongation upon theapplication of tensile forces. A woven structure of nylon yarns may bepreferred.

[0032] In the event that a ring element 132 is utilized, it ispreferably formed from a smooth surface material of high strength suchas metal or the like. Such materials have the ability to withstandsubstantial loading without undergoing plastic deformation. As will bediscussed further hereinafter, the ring element 132 may pass in slidingrelation over a stationary retaining member which extends through theopening in the ring element 132 such that the ring element 132 may bepulled away from the retaining member when tension is applied to theanchor strap 131. In the event that a ring element 132 is not utilized,it is contemplated that this function may be carried out by the loop 133which may likewise accept the retaining member therein. Thus, it is tobe appreciated that the use of the ring element 132 is in no wayconsidered to be critical to the performance of the present invention.Moreover, while the illustrated and potentialy preferred embodimentutilizes a female member such as the ring element 132 or loop 133disposed in sliding relation over a male retaining member, it islikewise contemplated that such female elements may be substituted witha male element for disposition in sliding relation within a supportingfemale retaining member if desired.

[0033] As best seen in FIG. 2, according to one embodiment of thepresent invention, an actuation mechanism 136 including a supportstructure 138 is operatively connected to a gas emitting inflator 140which is activated by an initiator 141 such as a pyrotechnic squib orother suitable device as will be well known to those of skill in theart. The gas emitting inflator 140 is stored within a housing 142 whichmay include one or more vent openings 143 for transmission of inflatorgas outwardly from the module away from the air bag 120. As illustrated,such vent openings 143 are normally in fluid communication with gasdischarge ports 144 generally surrounding the diffuser portion 145 ofthe inflator 140. As will be appreciated, while the support structure138 of the actuation mechanism 136 is illustrated as being connected tothe gas emitting inflator 140, it is likewise contemplated that anynumber of other arrangements may also be utilized. By way of exampleonly, it is contemplated that the actuation mechanism 136 may be locatedremote from the inflator 140 and attached directly to the housing 142.

[0034] According to the illustrated embodiment, the ring element 132 orloop 133 on the anchor strap 131 is disposed in sliding relation over arestraining stud 148 which is secured in substantially stable relationto the housing 142. The restraining stud 148 is disposed in butting ornotched relation to a tether blocking element 149 such as a plate ornotched post. As will be appreciated, in such an arrangement the ringelement 132 or loop 133 will be anchored in place with the restrainingstud 148 and tether blocking element 149 preventing the withdrawal ofthe ring element 132 or loop 133 thereby holding the anchor strap 131 inplace. The tethered restraints 130 which are fixedly attached to theanchor strap 131 will likewise be anchored against outward movement asbest seen in FIG. 3A. Accordingly, the expanded profile of the air bag120 is limited due to the anchored relation between the anchor strap 131and the stationary restraining stud 148.

[0035] According to the illustrated embodiment, the tether blockingelement 149 is carried within a plunger element 150 which is held withinthe interior of the support structure 138 at the end of the inflator140. The support structure 138 preferably has a substantially hollowtubular shape including interior walls 139 defining an axial openinginto which the plunger element 150 and an initiator device 160 may beinserted during assembly.

[0036] The support structure 138 preferably includes a first support end170 of a substantially flanged configuration that is secured directly tothe head portion of the inflator 140. The first support end 170 of thesupport structure 138 may be secured to the inflator 140 by any suitablemethod, such as welding. The support structure 138 also preferablyincludes a spacing shoulder 174 which is sized larger than an endopening in the housing 142 such that the support structure 138 islimited from going through the end opening within the housing 142 and isproperly positioned during assembly. The spacing shoulder 174 ispreferably integrally formed with the support structure 138 such as bymachining or molding but may also be provided as a separate pieceattached to or slipped over the support structure 138. In the installedcondition, the spacing shoulder 174 preferably abuts an end wall of thehousing 142.

[0037] According to the illustrated embodiment, the support structure138 is externally attached to the inflator 140 and may be provided as anassembly with the inflator 140 or may alternatively be integrally formedwith the inflator 140. The support structure 138 preferably includes afirst guide channel 176 which extends longitudinally along at least aportion of the distance between the spacing shoulder 174 and the firstsupport end 170 of the support structure 138 such that the tetherblocking element 149 passes through the first guide channel 176 and intothe plunger element 150 as shown. The support structure 138 furtherpreferably includes a threaded end portion 178 which extends past thespacing shoulder 174 through the end opening of the housing 142 formating with a cap nut 180 to secure the inflator 140 and the actuationmechanism 136 to the housing 142.

[0038] The plunger element 150 is preferably integrally formed from aplastic material and has a generally cylindrical shape. The plungerelement 150 is preferably seated within the interior walls 139 of thesupport structure 138 and has a diameter which is slightly smaller thanthe axial opening between the interior walls 139 such that the plungerelement 150 is slidable relative to the interior walls 139. The plungerelement 150 includes at least a first radial opening which is sized forthe receipt of the tether blocking element 149. The plunger element 150may also include a second radial plunger hole for the receipt of amoveable vent blocking device 185 the operation of which will bedescribed further hereinafter. However, it is also contemplated that theactuation mechanism 136 or such other mechanism as may be used toregulate the expanded configuration of the air bag 120 may be operatedwithout such a moveable vent blocking element 185 if desired. Theelements received within the linear plunger element 150 may be securedin place by snap-fitted attachment, although it will be appreciated thatother methods of attachment including by way of example only crimping,fastening, or adhesion may also be utilized to obtain secure attachment.

[0039] As shown, the plunger element 150 includes a shear feature 152which is illustrated as a flange located at the end of the plungerelement 150. The shear feature 152 is preferably integrally formed withthe plunger element 150, but may also be a separate piece attached tothe plunger element 150. The shear feature 152 is sized larger than theaxial opening within the support structure 138 such that the sheerfeature 152 engages the support structure 138 during insertion to limitthe insertion of the plunger element 150 into the support structure 138.

[0040] The plunger element 150 preferably includes an axial plunger bore154 in which the initiator device 160 such as a pyrotechnic squib,pneumatic actuator or the like is seated prior to activation. Theinitiator device 160 preferably is activated in response to a signalfrom a control device such as an on-board computer (not shown) basedupon inputs from the seat position sensor 122, optical scanner 124 andany other sensor as may be used to measure the nature of the occupantand the severity of the event taking place. Upon activation, theinitiator device 160 produces a pressure wave that presses against aplunger reaction surface 157. The application of such force causes theshear feature 152 to break off and permits the plunger element 150 toslide within the support structure 138 until engaging the head of theinflator 40 which acts as a stop surface.

[0041] In the event that a vent blocking element 185 is to be utilizedin conjunction with the actuation mechanism 136, the vent blockingelement 185 will preferably include an upwardly projecting arm portion186 which may be snap fittedly attached in the plunger element 150. Thevent blocking element 185 will also preferably include a slide portion187 extending at generally a right angle to the arm portion 186. Thus,in the illustrated embodiment wherein the vent blocking element 185 isto be utilized, the restraining stud 148, tether blocking element 149,and vent blocking element 185 are arranged in a substantially “Z” shapedcross sectional profile.

[0042] The slide portion 187 preferably has a generally curved shapesuch that allows the insertion into the housing 142 through round endwall openings during the assembly process. The vent blocking element 185is preferably moveable within a second guide channel 177 within thesupport structure 138 so as to close an inflator vent opening 143 uponactivation of the initiator device 160. In FIG. 2, the slide portion 187is shown in a first position in solid lines in which the inflator ventopening 143 is open thereby lowering the amount of gas available forinflation of the air bag 120 and is illustrated in phantom lines in asecond position in which the slide portion 187 is blocking the inflatorvent opening 143 within the housing 142 thereby directing a largerquantity of available inflator gas into the air bag 120.

[0043] Prior to activation of the inflator 140 the air bag 120 is storedin a folded condition atop the inflator 140. Also, prior to activationof the inflator 140, the tether blocking element 149 as well as theoptional vent blocking element 85 are held in a first position by theshear feature 52 such that the restraining stud 148 and tether blockingelement 149 hold the anchor strap 131 in place. In addition, the slideportion 187 of the vent blocking element 185 is misaligned with theinflator vent opening 143 such that the inflator vent opening 143 isopen thereby permitting the egress of inflator gas outwardly from thehousing 142.

[0044] Upon sensing predetermined vehicle and occupant conditions, asignal is sent to the inflator initiator 141 thereby activating theinflator 140. Based upon the measurement of occupant conditionsincluding the position and/or physical character of the occupant 114 asmeasured by the seat position sensor 122, optical scanner 124 and othersensors as may be utilized, a signal is also sent to the initiatordevice 160 advising the initiator device 160 as to whether the firstposition is to be maintained or whether the initiator device 160 is tobe activated at a predetermined time during activation of the inflator140 to move the tether blocking element 149 thereby permitting theanchor strap 131 to slide away from the restraining stud 148. Accordingto the potentially preferred arrangement, the initiator device 160 willbe activated when conditions indicate that an air bag of deeper profileand larger volume is required and will remain in a deactivated statewhen conditions indicate that an air bag of more shallow profile andlower volume is desirable.

[0045] As previously indicated, upon activation the initiator device 160produces a pressure wave which presses against the reaction surface 157of the plunger element 150 and quickly forces the plunger element 150towards the head portion of the inflator 140. This movement carries thetether blocking element 149 as well as any optional vent blockingelement 185 within the plunger element 150 from the first positionillustrated in FIG. 2 to a second position wherein the plunger element150 is in contact with the head portion of the inflator 40. Suchmovement rapidly opens a path of egress for the ring element 132 or loop133 disposed over the restraining stud 148 thereby permitting the ringelement 132 or loop 133 to slide out of engagement with the restrainingstud 148 as tension is applied to the anchor strap 131. This tensionarises due to the outward expansion of the air bag 120 as it is filledwith inflator gas. Preferably such tension will include both ahorizontal as well as a vertical force component arising from the angledrelation between the anchor strap 131 and the restraining stud 148 so asto promote sliding disengagement from the restraining stud 148.Simultaneously with such disengagement, the vent blocking element 185covers the vent opening 143 thereby increasing the quantity of inflationgas available to inflate the air bag 120.

[0046] In FIG. 3A the air bag 120 of FIG. 2 is illustrated in aninflated restrained condition wherein an arrangement of tether elements130 is held in a shortened configuration at the restraining stud 148. Asshown, according to the illustrated arrangement the tether elements 130are formed from a length of material which preferably passes in slidingrelation through loop structures 190 at the surface of the air bagcushion 120. In addition, the tether elements 130 are preferably fixedlyattached at their ends to secure points of attachment 191 which may beeither internal or external to the air bag 120. Attachment using sewnseams at the interior of the air bag 120 may be preferred although othermeans of attachment as are known to those of skill in the art may alsobe used.

[0047] According to the illustrated embodiment, the portion of thetether elements 130 between the loop structures 190 is drawn down to therestraining stud 148 either directly or via the anchor strap 131 andheld in a shortened condition by the restraining stud 148. This drawingoperation is made possible by the sliding relation between the tetherelements 130 and the loop structures 190 at the surface of the air bag120. As will be appreciated, as the tether elements 130 are pulledtowards the restraining stud 148 the effective length of the tetherelements is diminished thereby diminishing the available depth of theair bag 120. However, the air bag 120 is nonetheless capable of outwardexpansion to the degree permitted by the remaining length extendingthrough the loop structures 190 between the secure points of attachment191. While only a single length of tether material extending through twoloop structures is illustrated, it is likewise contemplated thatadditional lengths of tether forming material extending throughadditional loops may also be utilized to obtain expansioncharacteristics as may be desired.

[0048] As illustrated in FIG. 3B, upon release of the tether elements130 from restraint at the restraining stud 148 in the manner asdescribed above, the air bag 120 expands outwardly to an extendedprofile as the tether elements slide through the loop structures 190.However, according to the potentially preferred arrangement, theextended profile is nonetheless restrained to some degree by the secureattachment of the ends of the tether elements 130 at the secure pointsof attachment 191. The maintenance of such a tethering relationshippermits the air bag 120 to adopt a generally deep elongated profile asshown without requiring the actual volumetric capacity to besubstantially increased. The actual increase in such volumetric capacityis contemplated to be in the range of about 25% or less and may be inthe range of about 15% or less.

[0049] In FIG. 4A there is illustrated another variable profile air bagarrangement wherein elements are designated by like reference numeralsto those used in FIGS. 3A and 3B but with a prime. As shown, accordingto this embodiment, a length of material forming the tether element 130′is preferably passed in sliding relation through two loop structures190′ such as sewn loops of textile material on the surface of the airbag 120′. One end of the tethering element 130′ is held in place at apoint of secure connection 191′ which may be either internal or externalto the air bag 120′. The other end of the tethering element 130′ is heldin place by the ring element 132′ or formed loop 133′ at the restrainingstud 148′ between the end wall of the housing 142′ and the tetherblocking element 149′. As illustrated, such an arrangement gives rise toan increased horizontal force component when tension is applied by theexpansion of the air bag 120′. An anchor strap 131′ joins the section ofthe tethering element 130′ adjacent to the connection with the retainingstud 148′ to a point of secure connection 192′. As will be appreciated,it is contemplated that the relative position of the loop structures190′ and the points of secure connection 191′ and 192′ may be reversedif desired.

[0050] As illustrated in FIG. 4B, upon release of the tether element130′ from the restraining stud 148′ in the manner as described above,the air bag 120′ expands outwardly to an extended profile. However,according to the potentially preferred arrangement, the extended profileis nonetheless restrained by the secure attachment of the tether element130′ and the anchor strap 131′ at their respective secure points ofattachment 191′, 192′. The maintenance of such a tethering relationshippermits the air bag 120′ to adopt a generally deep elongated profile asshown without requiring the actual volumetric capacity to besubstantially increased. The actual increase in such volumetric capacityis contemplated to be in the range of about 25% or less and may be inthe range of about 15% or less.

[0051] As will be appreciated, the enhanced angled relation of thetether element 130′ with respect to the restraining stud 148′ enhancesthe horizontal component of the force vector extending along the tetherelement 130′ when the tether element 130′ is placed into tension as theair bag 120′ is deployed. This enhanced horizontal force component isbelieved to aid in the sliding disengagement of the tether element 130′away from the restraining stud 148′. In addition, the use of therestraining strap 131 ′ provides additional control over the tetherelement 130′ and any ring element 132′ as may be utilized. While only asingle length of tether material extending through two loop structuresis illustrated, it is likewise contemplated that additional lengths oftether forming material extending through additional loops may also beutilized to obtain expansion characteristics as may be desired.

[0052] It is contemplated that the use of the variable profile air bagaccording to the present invention will permit a single cushion to beutilized to effectively protect a wide range of occupants by having theair bag conform to the requirements of such occupants. In particular, itis contemplated that it will be possible to avoid substantial divergencebetween the forces to which occupants of different physical dimensionsmay be subjected during interaction with the air bag.

[0053] As indicated previously, while measurements relating to theposition and/or size of the occupant to be protected may be used todetermine whether or not to release the profile restraining tetherelements during an impact event of given severity, it is likewisecontemplated that other factors may also be utilized. By way of exampleonly, it is contemplated that the velocity of the vehicle 110 may beused as an overriding factor in the determination as to whether or notan enhanced profile is desired. In particular, it is contemplated thatminimum velocity thresholds may be preprogrammed into the on-boardcomputer or other control device as may be utilized such that enhancedprofile will not be obtained if the vehicle is traveling at a very lowvelocity which is likely to give rise to a collision of low severity.

[0054] It is to be understood that while the present invention has beenillustrated and described in relation to potentially preferredembodiments, constructions, and procedures, that such embodiments,constructions, and procedures are illustrative only and that the presentinvention is in no event to be limited thereto. Rather, it iscontemplated that modifications and variations embodying the principlesof the present invention will no doubt occur to those of skill in theart. It is therefore contemplated and intended that the presentinvention shall extend to all such modifications and variations as mayincorporate the broad aspects of the present invention within the fullspirit and scope thereof.

1. An air bag assembly for cushioning restraint of an occupant in avehicle during an impact event, the air bag assembly comprising: aninflator activatable to discharge inflation gas upon the occurrence ofpredetermined vehicle conditions; an air bag cushion including aninterior surface in fluid communication with the inflator such that upondischarge of inflation gas from the inflator the air bag cushion isinflated to a deployed state from a location of deployment insubstantially opposing relation to the occupant; at least one profilerestraining tether element operatively connected to the air bag cushionsuch that the profile restraining tether element restrains the expansionof the air bag cushion upon introduction of the inflation gas to the airbag cushion, the profile restraining tether element further beingreleasably anchored to a substantially stationary retaining member so asto shorten the operative length of the profile restraining tetherelement such that the air bag cushion is inflatable to a firstrestrained depth when the profile restraining tether element is anchoredto the retaining member, the profile restraining tether element beingreleasable from the retaining member upon the occurrence ofpredetermined occupant conditions at the time the air bag cushion isdeployed such that the air bag cushion is inflatable to a second depthwhich is greater than said first restrained depth when saidpredetermined occupant conditions occur.
 2. The invention according toclaim 1, wherein the profile restraining tether element extends fromfixed points of connection on the air bag cushion through one or moreloop elements at the interior surface of the air bag cushion.
 3. Theinvention according to claim 2, wherein the profile restraining tetherelement is releasably anchored to the retaining member by a femaleelement extending in sliding relation over the retaining member.
 4. Theinvention according to claim 1, wherein a moveable barrier element isdisposed adjacent to the retaining member such that an anchoringrelation is maintained between the retaining member and the profilerestraining tether element until the moveable barrier element is movedaway from the retaining member.
 5. The invention according to claim 4,wherein the profile restraining tether element extends in angledrelation away from the retaining member such upon movement of themoveable barrier element away from the retaining member the applicationof tension to the profile restraining tether element causes the profilerestraining tether element to slidingly disengage from the retainingmember.
 6. The invention according to claim 1, wherein the air bagassembly further comprises an actuatable variable inflation device tocontrol the amount of inflation gas discharged into the air bag cushion.7. The invention according to claim 6, wherein the variable inflationdevice is actuated in conjunction with the release of the profilerestraining tether element utilizing a single initiator therebydirecting additional inflation gas into the air bag cushion upon releaseof the profile restraining tether elements.
 8. An air bag assembly forcushioning restraint of an occupant in a vehicle during an impact event,the air bag assembly comprising: an inflator having an initiatoractivatable to discharge inflation gas upon the occurrence ofpredetermined vehicle conditions; an air bag cushion having an interiorsurface in fluid communication with the inflator such that upondischarge of inflation gas from the inflator the air bag cushion isinflated to a deployed state from a location of deployment insubstantially opposing relation to the occupant, at least one profilerestraining tether element releasably anchored to a substantiallystationary retaining member thereby shortening the operative length ofthe profile restraining tether element; an actuatable inflation controldevice; and an actuation mechanism including an initiator activatable inresponse to a signal based upon input data from one or more sensorsmeasuring conditions of the occupant such that the actuation mechanismreleases the profile restraining tether element from the retainingmember and conjunctively directs additional inflation gas into the airbag upon the occurrence of predetermined occupant conditions at the timethe air bag cushion is deployed such that the inflatable profile of theair bag is increased in instances when said predetermined occupantconditions occur.
 9. The invention according to claim 8, wherein theprofile restraining tether element extends from fixed points ofconnection on the air bag cushion through one or more loop elements atthe interior surface of the air bag cushion.
 10. The invention accordingto claim 8, wherein the profile restraining tether element is releasablyanchored to the retaining member by a female element extending insliding relation over the retaining member.
 11. The invention accordingto claim 8, wherein a moveable barrier element is disposed adjacent tothe retaining member such that an anchoring relation is maintainedbetween the retaining member and the profile restraining tether elementuntil the moveable barrier element is moved away from the retainingmember.
 12. The invention according to claim 11, wherein the profilerestraining tether element extends in angled relation away from theretaining member such that upon movement of the moveable barrier elementaway from the retaining member the application of tension to the profilerestraining tether element causes the profile restraining tether elementto slidingly disengage from the retaining member.
 13. The inventionaccording to claim 12, wherein the profile restraining tether element isreleasably anchored to the retaining member by a ring elementoperatively connected to a strap element attached to the profilerestraining tether element.
 14. The invention according to claim 12,wherein the profile restraining tether element is releasably anchored tothe retaining member by a loop formed on a strap attached to the profilerestraining tether element.
 15. The invention according to claim 8,wherein the actuation mechanism comprises a pyrotechnic initiator deviceactivatable during operation of the inflator and a moveable plungerhaving a reaction surface, wherein a moveable barrier element isattached to the plunger adjacent to the retaining member, and whereinthe initiator device is capable of generating pressure against thereaction surface of the plunger to move the plunger such that themoveable barrier element is carried away from the retaining memberthereby permitting the tether element to disengage from the retainingmember upon the application of tension to the tether element as the airbag cushion is inflated.
 16. The invention according to claim 8, whereinthe actuatable inflation control device comprises a moveable memberalignable with a vent opening within a housing containing the inflator,the moveable member being moveable relative to the vent opening uponactivation of the actuation mechanism thereby closing the vent openingin conjunction with release of the tether element from the retainingmember to increase the amount of inflation gas discharged into the airbag as the inflatable volume of the air bag is increased.
 17. An air bagassembly for cushioning restraint of an occupant in a vehicle during animpact event, the air bag assembly comprising: an inflator having aninitiator activatable to discharge inflation gas upon the occurrence ofpredetermined vehicle conditions; an air bag cushion having an interiorsurface in fluid communication with the inflator such that upondischarge of inflation gas from the inflator the air bag cushion isinflated to a deployed state from a location of deployment insubstantially opposing relation to the occupant, at least one profilerestraining tether element releasably anchored in to a substantiallystationary retaining member thereby shortening the operative length ofthe profile restraining tether element, an actuatable inflation controldevice; and an actuation mechanism comprising a single initiatoractivatable during operation of the inflator in response to a signalbased upon input data from one or more sensors measuring characteristicsof the occupant such that upon activation of said single initiator, theactuation mechanism releases the profile restraining tether element fromthe retaining member and conjunctively directs additional inflation gasinto the air bag upon the occurrence of predetermined occupantcharacteristics at the time the air bag cushion is deployed such thatthe inflatable profile of the air bag is increased in instances whensaid predetermined occupant characteristics occur.
 18. The inventionaccording to claim 17, wherein the actuation mechanism comprises amoveable plunger having a reaction surface, wherein a moveable barrierelement is attached to the plunger adjacent to the retaining member, andwherein the single initiator generates pressure against the reactionsurface of the plunger to move the plunger such that the moveablebarrier element is carried away from the retaining member therebypermitting the profile restraining tether element to slidingly disengagefrom the retaining member upon the application of tension to the profilerestraining tether element as the air bag cushion is inflated.
 19. Theinvention according to claim 18, wherein the actuatable inflationcontrol device comprises a moveable member alignable with a vent openingwithin a housing containing the inflator, the moveable member beingmoveable relative to the vent opening upon activation of the actuationmechanism thereby closing the vent opening in conjunction with releaseof the tether element from the retaining member to increase the amountof inflation gas discharged into the air bag as the inflatable volume ofthe air bag is increased.